SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edb6319ddaf713b9114823de641a30a84f250f9186a81d80abdd133bc3bd9b29' 
  AND token = 'Znt1JaHd3StmfEue4ezcppZ0qqqpR8+9VEsMgiyNT+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}